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Vitrigraph bubbles and craters

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Vitrigraph bubbles and craters

Postby l.sorg » Wed Mar 07, 2018 8:56 am

I've been using Bullseye glass since 2013, this is my first forum post question. I'm having an issue with vitrigraph. I am using the vitrigraph as shapes to create abstract designs, and in the initial full fuse of the vitrigraph to the glass sheet I am ending up with small bubble/craters in some places - usually at a place where the vitrigraph stringer is fatter than the stringer before or after that place. The size of these bubbles/craters range from 1 to 3 mm (sometimes they are bubbles and sometimes they are collapsed craters. My guess is that there is air trapped in the stringer at this place and it can't escape. I've adjusted the time for the bubble soak stage from my normal fuse schedule, but I'm still receiving the same result. My most recent adjusted schedule is: 300/1100/0 - 150/1240/60 - 400/1440/10 - AFAP/960/60 - 150/700/0. The kiln is Evenheat GTS 2541-13. I have been fusing two vitrigraph stringers, Red Tomato and Black, on separate glass projects and am having the same bubble/crater issue with both. Assistance with this issue is appreciated.

Thanks, Lee
l.sorg
 
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Re: Vitrigraph bubbles and craters

Postby jestersbaubles » Fri Mar 09, 2018 7:42 pm

If you are trying for a bubble squeeze, the ramp from 1100 to 1240 should be much slower. I usually ramp at 50/hr.

Also, if you are using BE glass, you are annealing at the wrong temp. BE currently recommends 900 deg F.

Dana W.
Dana Worley Fused Glass Designs
dba Jester's Baubles
http://www.jestersbaubles.com
http://www.jestersbaubles.blogspot.com
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Re: Vitrigraph bubbles and craters

Postby l.sorg » Sun Mar 11, 2018 10:28 am

Thanks for the schedule adjustment suggestions, Dana.

It turns out the main problem is in the schedule that I've been using to make the vitrigraph itself. Air is in the stringers which is causing the creation of the bubbles when I go to full fuse on the sheet glass — so, need to do a longer bubble soak when creating the vitrigraph. If someone has a recommended vitrigraph schedule, would love to see it. Thanks.
l.sorg
 
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